We review the literature on swimming in complex fluids. A classification is proposed by
comparing the length-and timescales of a swimmer with those of nearby obstacles …

Collective migration—the directed, coordinated motion of many self-propelled agents—is a
fascinating emergent behavior exhibited by active matter with functional implications for …

We show that a two-dimensional system of flocking active particles interacting
hydrodynamically can be expressed using a Hamiltonian formalism. The Hamiltonian …

We study the structure and dynamics of the interface separating a passive fluid from a
microtubule-based active fluid. Turbulent-like active flows power giant interfacial …

The scalings of the Rayleigh-Taylor instability are studied numerically for porous media
flows when the denser fluid lying on top of the less dense one is also much more viscous …

The dynamics and stability of a swarm of microswimmers is examined here using a
thermodynamically compliant microswimmer model. The theory presented in this work is a …

A key feature of many living systems, such as bacteria and eukaryotic cells, is their ability to
actively self-propel. Indeed, cellular motility underlies numerous critical biological …

Active fluids consume fuel at the microscopic scale, converting this energy into forces that
can drive macroscopic motions over scales far larger than their microscopic constituents. In …

A Hele-Shaw cell is a device used to study fluid flow between two parallel plates separated
by a small gap. The governing equation of flow within a Hele-Shaw cell is Darcy's law, which …

The behavior of fluid interfaces far from equilibrium plays central roles in nature and in
industry. Active swimmers trapped at interfaces can alter transport at fluid boundaries with …